The US Centers for Disease Control and Prevention has recorded 9,245 cases of “breakthrough” infections in people vaccinated against coronavirus, an official said Wednesday, but the evolution of new variants may make these vaccine failures more common.
“As of April 26th, among 95 million people who were fully vaccinated in the US, 9,245 breakthrough infections have been reported through national passive surveillance,” the CDC’s Dr. Heather Scobie told a meeting of the agency’s Advisory Committee on Immunization Practices.
Passive surveillance means the CDC is not actively looking for cases of people who develop infections, so the true case count is likely higher.
What health officials are really worried about are new variants or the virus that reduce vaccine effectiveness. As effectiveness goes down, more breakthrough cases can be expected. Scobie said the CDC will start measuring this.
“Starting soon, a CDC project with Emerging Infections Program sites should allow estimation of the frequency of SARS-CoV-2 variants among vaccinated and unvaccinated people in the US,” she said.
But CDC is planning on vaccine makers having to refresh their vaccine formulations to match the evolving virus, Scobie said. “Periodic update of SARS-CoV-2 vaccines is likely to be needed,” she said.